So far, hurricane warnings have issued for Puerto Rico, Virgin Islands due to the possibility of Irma's arrival.

As of Monday evening, the National Hurricane Center has issued a Hurricane Warning for the following: Antigua, Barbuda, Anguilla, Montserrat, St. Kitts, Nevis, Saba, St. Eustatius, and Sint MaartenSaint Martin and Saint Barthelemy, British Virgin Islands, U.S. Virgin IslandsPuerto Rico, Vieques and Culebra.

As of 5 p.m. ET, Monday, Irma was about 490 miles (790 kilometers) east of the Leeward Islands, the National Hurricane Center said. It is packing maximum sustained winds of 130 mph (215 kph) as it heads west at 13 mph (20 kph). Landfall is expected early Wednesday on the island of Anguilla.

Computer models show the system moving through the Caribbean, and by the end of week, it will turn right toward the north, said CNN meteorologist and weather anchor Tom Sater.

"There is a small window. If it turns sooner rather than later, we could maybe see the system slide by the East Coast into the ocean, but that window is shutting quickly," Sater said. "It definitely looks like we will be impacted by a major hurricane that is a Category 3, 4 or 5."

The hurricane center said swells generated by Irma would begin impacting the northern Leeward Islands on Monday.

"These swells are likely to cause life-threatening surf and rip current conditions," the NHC said.

A string of Caribbean islands are now under hurricane warnings, including Antigua, Barbuda, Anguilla, Montserrat, St. Kitts, Nevis, Saba, St. Eustatius, St. Martin/Sint Maarten and St. Barts, the hurricane center said.

"A hurricane warning means that hurricane conditions are expected somewhere within the warning area," the hurricane center said. "A warning is typically issued 36 hours before the anticipated first occurrence of tropical-storm-force winds, conditions that make outside preparations difficult or dangerous. Preparations to protect life and property should be rushed to completion."

And Irma will only intensify in the coming days, CNN meteorologist Allison Chinchar said. "Over the coming days, it's going to get into that warmer water. That's going to help the storm intensify."

Puerto Ricans warned

Irma is expected to remain a "dangerous major hurricane" through the week and could directly affect the British and US Virgin Islands, Puerto Rico, Hispaniola, Turks and Caicos, and the Bahamas, the agency said.

Puerto Rico Gov. Ricardo Rosselló warned the public on Sunday that the island could feel Irma's wrath around noon Wednesday.

Puerto Rico's disaster management agency, AEMEAD, is monitoring Irma and has opened an information hotline.

Florida governor says be prepared

It's too soon to know the impact Irma could have on the continental United States, where no warnings or watches are in effect.

"Regardless, everyone in hurricane-prone areas should ensure that they have their hurricane plan in place, as we are now near the peak of the season," the National Hurricane Center said.

Chinchar said Irma could affect not just the eastern coast of Florida, but also farther up the East Coast.

"If there was a US landfall, we're talking a week from today," Chinchar said Monday.

"FL knows how important it is to be prepared. Encourage your loved ones to have a plan ahead of any potential storm," Scott tweeted Sunday. "Disaster preparedness should be a priority for every Florida family."

Why Irma could be especially intense

Irma is a classic "Cape Verde hurricane," meaning it formed in the far eastern Atlantic, near the Cape Verde Islands (now known as the Cabo Verde Islands), before tracking all the way across the Atlantic, CNN meteorologist Brandon Miller said.

And Cape Verde storms frequently become some of the largest and most intense hurricanes. Examples include Hurricane Hugo, Hurricane Floyd, and Hurricane Ivan.